Experimental Study On Pseudo-static Test Of Short-limb Shear Wall Joints

In recent years,short-limb shear wall have been widely used in practical engineering,but no exact calculation formula has been given in the code.The calculation of the short-limb shear wall reference the calculation formula of the special-shaped column or shear wall.Domestic and foreign scholars have done a lot of research on short-limb shear wall,but the research on seismic performance and energy dissipation capacity of short-limb shear wall is relatively less.Because of the complex force on the joints of the short-limb shear wall,the research on it is not very comprehensive,in order to study the variation of the force more deeply,this paper makes four specimen models according to the 1:3 ratio by changing the different ratio of limb thickness.The quasi-static test is carried out,and the numerical simulation method is applied to further expand the research.The main work of this paper is as follows:1.Quasi-static tests were carried out on specimens with different limb thickness ratios,the crack development was observed during the whole process,then the hysteretic curves,skeleton curves,ductility,equivalent viscous damping coefficient(positive and reverse loading or unloading)and stiffness degradation of each component were compared and analyzed,the formula and curve of stiffness degradation of positive and reverse loading or unloading are fitted,at last,the strain of concrete and steel bar is analyzed.2.The experimental results show that with the increase of limb thickness ratio,the bearng capacity of the member increases,but the displacement ductility decreases,and the energy dissipation capacity of the structure does not increase with the increase of the limb thickness ratio,the energy dissipation capacity of the specimen with the limb thickness ratio of six is relatively strong.Because of the asymmetry of the structure itself,the flange of each member is pulled,and the bearing capacity of flange under tension and web under compression is stronger than that of the flange under compression and the web is under tension.3.The results of ANSYS numerical analysis are in good agreement with the experimental results.After that,changing axial compression ratio,concrete strength grade and limb thickness are further studied.The effects of changing concrete strength and stress on seismic performance and energy dissipation performance of joint model are analyzed.4.The experimental and simulated data are analyzed synthetically,and the three-fold skeleton curve model of T-shaped short-limb shear wall joint is established by using the method of test fitting,and the hysteretic curve is combined on the basis of the three-fold line skeleton curve model,the restoring force model of T-shaped short-limb shear wall joints is established,and the hysteretic rules are determined.Finally,the calculation formulas of unloading stiffness K2 x and K4 x in the restoring force model are deduced.